The four handy knobs can act as active attenuators (unipolar) or attenuverters (bipolar) depending on the setting of the two-position switches above each one.

Each input is normalled to a precision +5V DC voltage source. With nothing plugged into the jacks, each knob controls a voltage range of 0 to +5 v or -5 to +5 v depending on the position of the mode switch.##2 modes for each channel##5v normalled to each input##With external signals it acts as active/buffered attenuator/attenuverter/mixer##Each output normalled to mix into the adjacent channel on the right making it possible to do sub mixes in groups of 2, 3 or all four channels.